# 用async改写以下程序
#
# 参考库 asyncio

import time


def task(number):
    print(f"task {number} start at: {time.time()}")
    print(number)
    time.sleep(number)
    print(f"task {number} end at: {time.time()}")
1

def main():
    work_queue = [4, 3, 2, 1]

    for work in work_queue:
        task(number=work)


if __name__ == "__main__":
    main()
